UNIT 1 Past paper questions

• biological catalysts


  Protein that is found in our bodies catalyst speeds up reactions without being used up
• what is a mutation 


  a change in the base sequence in dna
• name three types of mutations

  substitution

  deletion

  insertion
• prothrombin is converted to thrombin by

  thromboplastin
• the active site of thrombin binds to fringes and as a result mesh fivers and clots is formed
• which type of drug is warfarin

  an anticoagulant
• amino acids are joined together by peptide bonds in a condensation reaction
• saturated lipids have a lower carbo:hydrogen ratio than unsaturated lipids
• saturated lipids are straight
• unsaturated lipids are curly
• what type of bonding do rna molecules have

  phosphodiester bonds

  hydrogen bonds between the bases

  hydrogen bonds that hold the strands
• genotype

  combination of alleles
• gene

  is a sequence of bases that code for a polypeptide chain
• allele


  is diff forms of the gene
• phenotype


  the physical characteristics expressed
• type of bond found in phospholipids

  ester
• cardiac cycle stages

  ventricular systole

  arteial systole

  cardiac diastole
• how structure of capillaries relates to its function

  one cell thick with thin walls for quick diffusion
• why veins have valves

  to prevent back-flow of blood so blood doesn’t return to the heart
• ratio of glycerol to fatty acid

  1:3
• semi-conservative replication

  an increase in the number of dna molecules each molecule consists of one original and one new strand
• enzymes that are involved in semi-conservative replication

  DNA helicase

  DNA ligase

  DNA polymerase
• state which side of the heart pumps blood at high pressure

  left
• difference in pressure between the left and the right side of the heart

  left side has thicker, muscular walls and can pump blood with a greater force
• explain how the structure of a flatworm is adapted to obtain oxygen from the water

  the flatworm has a large surface area to volume ratio

  there is a short diffusion distance so diffusion is faster
• explain why many animals need a heart and circulatory system

  • heart is needed to pump blood around the body

  • many animals have a small SA:V ratio

  • circulatory system is needed to overcome the limitations of diffusion

  • oxygen and co2 transported in blood

  • many animals have a higher metabolic rate
• advantage of a double circulatory system

  • for organisms with a low SA:V diffusion alone will be insufficient

  • differential pressure

  -lower pressure to lungs prevent damage to the capillaries so no efficient gas exchange

  -higher pressure to body for efficient delivery of oxygen and glucose

  • enables organisms to have a high metabolic rate
• define mass flow

  is the movement of fluids down a pressure gradient
• explain why water is a good solvent

  • the oxygen is slightly negative and hydrogens are slightly positive

  • water surrounds polar molecules allowing them to dissolve and hydrogen bonds form
• The structure of collagen

  • Fibrous protein

  • triple stranded helix held by hydrogen bonds

  • short repeating sequences of amino acids
• Why statins reduce the risk of CVD

  • Control the production of cholesterol in the liver

  • reducing the blood cholesterol levels

  • raise HDL level lowers the LDL
• risks of using statins to treat CVD

  Muscle pain

  headache

  dizziness

  diabetes
• Define casual relationship

  A direct cause and effect relationship between the independent and dependent variables
• Structure differences between LDL and HDL

  • LDL is larger and have less protein

  • HDL is smaller and has more protein
• Factors that increase CVD levels

  Smoking

  inactivity

  obesity

  high cholesterol/blood pressure
• Risk associated with statins

  Could trigger muscle inflammation
• How diuretics help reduce the risk of CVD

  Eliminates excess fluids to decrease blood volume and salt which decreases blood pressure
• Expressed as per 100000 of population

  • Populations of different countries will vary

  • for valid comparison
• Differences in the number of CVD in these countries

  • different healthcare

  • different education

  • different life style factors
• How reliability of investigation could be increased

  • Use more students/..

  • repetition